Transmitting the necessary information database to the client is complex and difficult at times, particularly when the client is a device that is permanently installed in a mobile platform such as a motor vehicle and cannot be easily separated from the mobile platform, e.g., like a laptop, and that may be connected to a stationary data network to receive the required information. Depending on the variability of the information database, various techniques have been used to provide the required information database for vehicle-supported clients. In the case of an engine control unit, for example, the variability of the information database is minimal. As a result, it usually suffices to permanently install the information database in the electronic control unit in the form of a non-volatile memory component. Updating the information database is not ruled out entirely, but it is difficult to do.
Other data processing devices in motor vehicles, such as vehicle navigation systems in particular, require a substantially more extensive information database that must also be updated from time to time to ensure the effectiveness of the navigation system. In this case, it is common practice to record the required information database or at least modifiable portions thereof on portable data carriers, in particular CD-ROMs, which can be utilized in a reading device of the navigation system. A method of this type is practicable when the frequency with which the data carriers must be updated is not too great. Navigation information that is updated daily or even hourly—which is required to avoid temporary obstacles such as construction sites and traffic jams—cannot be easily provided in this manner.
It is possible, in principle, to make information available quickly via wireless communication, in particular by a point-to-point dial-up connection in a mobile network, but this method is limited by the high connection costs and limited transmission bandwidths that result in significant transmission delays when large quantities of data are involved. Wireless transmission is therefore an option only for applications with very limited data requirements.